1. Field of the Invention
The present invention generally relates to the technical field of a conversion device of an electric power system using AC and DC power, and more particularly to a composite power supply having a variety of electric power ports, and capable of supplying electric power without requiring a power-on and capable of adjusting an output voltage.
2. Description of the Related Art
In general, a computer usually comes with a power supply for converting an external inputted 110V AC or 220V AC power into 12V DC or 5V DC or 3.3V DC power required by a motherboard, a CPU interface card, and various internal data access units (such as a hard disk, an optical disk drive or a card reader). As various portable electronic products such as mobile communication devices, notebook computers (NB), personal digital assistants (PDA) and multimedia players (MP4 or MP3 players) become increasingly popular and capable of satisfying user requirements for mobile communications, personal data management, data storage, and multimedia function, the portable electronic products of this type generally have a built-in power supply device provided for charging the portable electronic products repeatedly. After the electric power of a portable electronic product is exhausted, an electric charger can be used for charging the electronic product directly, or various transmission lines or electric power lines can be connected to respective ports (such as the USB port and SATA port) of a computer.
However, various portable electronic products come with electric chargers of various different specifications, and thus it is necessary for users to carry all these electric chargers. Obviously, it is extremely inconvenient to users and definitely an unnecessary waste. Furthermore, a general power supply of a computer cannot be used for supplying power to the portable electronic products or charging the portable electronic products directly, and it is necessary to turn on the computer first, and then use the USB port or SATA port provided on the motherboard to supply electric power to the portable electronic products or charging the portable electronic products in an inconvenient manner.
In view of the foregoing drawbacks of the conventional power supply, the present invention provides a composite power supply structure that provides various power output ports with different specifications to facilitate the connection of various portable electronic products such as a mobile communication device, a notebook (NB), a personal digital assistant (PDA) and a multimedia player. The present invention also has an adjusting structure of a variable output voltage, such that the requirements for supplying electric power and charging various portable electronic products can be satisfied without requiring a power-on.